Guardians of the Galaxy is one of the most overloaded movies I have ever seen. There are too many characters, too many strange alien locations, too many colors, too many jokes, too many villains. Luckily, director James Gunn does too much really well, and the film is chockfull of everything without being bloated. It is also the most fun I have had in a movie theater since I don’t even know when.

The movie opens with a young single mother dying of cancer. Her son, Peter, runs away from the hospital and is immediately abducted by a spaceship. The next time we see Peter he is on an abandoned alien planet dancing to Redbone’s “Come and Get Your Love” and stealing a powerful artifact. He isn’t sure what it is, but he knows a lot of people want it and he’s quick to pick up on its importance, asking if it’s a Maltese Falcon kind of thing. Pretty soon everyone is after him, including Gamora and Rocket Raccoon and Groot. They all form a loose alliance of mutual interest in prison, and Drax the Destroyer tags along for the chance to kill Ronan the Accuser, Gamora’s former boss. With the band together, things start happening.

The script by Nicole Perlman and James Gunn flings the band of misfits across the galaxy, from planet to spaceship to giant ancient space head, and each world is bright and colorful and full of interesting creatures. One of the joys of Guardians is that while it doesn’t shy away from darkness, it doesn’t feel the need to bludgeon us over the head with dark shadows and solemn colors we’ve become accustomed to. The movie is sincere and hopeful, more than any of the more conventional Marvel films. The characters all have tragic pasts, but they don’t spend all their time brooding. Peter Quill especially is open to joy and wonder in a really lovely way, inspired by his bizarre understanding of Footloose and the mix tape he carries everywhere, his only remembrance of home.

Chris Pratt plays Quill (although he prefers to be called Star-Lord), the leader of the unlikely heroes, and it is his movie from start to finish. We’ve seen him steal scenes as a supporting actor in Parks & Recreation and Deliveryman, but given a star vehicle of his own he rises to the occasion. He has the devil-may-care swagger of someone who has been surviving by his wits since he was a child, confident that he can take his way out of anything. And while he’s not had the greatest influences after he left Earth, he also has the heart of boy far from home who misses his mom. He may be a somewhat amoral, womanizing thief, but he is also boyishly open and sincere, with a deeply ingrained heroism.

That through line of decency leaves him open to the ministrations of Gamora,, the most dangerous woman in the galaxy, who has a new conscience and serves as the film's moral compass. Zoe Saldana plays her like a recovering child soldier, extraordinarily tough, but with an unspoken vulnerability, equal parts prideful and ashamed. Star-Lord saves her life in prison, and rather than grateful deference, she is unyielding in her demands of him. Dave Bautista as Drax the Destroyer is one those cases where a part and an actor are made for each other. Drax is a hulking brute whose brutism is a mask for unbearable, inarticulate grief, inarticulate because he has no capacity for figurative language or metaphor. It leads to a sometimes childlike honesty and also an unexpectedly fierce devotion.

The last two-fifths of the team are fully CG. Rocket, misanthropic (does misanthropic apply to alien races or just humans?), foul-mouthed, violent, anthropomorphic raccoon, is one the highlights of the film. Bradley Cooper’s voice work is funny and biting and hints at a heart buried underneath the bluster, but just barely. Rocket has great chemistry with Pratt’s Star-Lord, and for that I think the credit goes to Sean Gunn, who appears onscreen as Yondu’s sidekick Kraglin, but also served as Rocket’s stand in on-set, acting opposite the other cast members. As for Groot, well, Groot is a sentient tree who only speaks 3 words (SPOILER! 5 words, actually) the entire movie, and yet, he is a fully present, developed character. I don’t know if that is owing to the CG artists or to Vin Diesel’s voice, but it is an achievement.

As for the rest of the massive cast, Gunn deftly handles the various antagonists, giving them all screen time without shoehorning anyone in. The caliber of the actors he brought on to play small roles is a little bit astonishing, especially given the reportedly onerous demands of a Marvel contract. How did he get Benicio del Toro to sign on for 6-9 films as the Collector? Thanos is barely in the movie (although there is speculation that he will be the major villain in Avengers 3, years down the road), but Gunn talked Josh Brolin into a motion capture suit. In a film with such uniquely strange heroes, everyone who isn’t on the team is an antagonist, but the real villain of the piece is Lee Pace’s Ronan the Accuser and his haughtiness suits the part well.. Ronan wants to destroy a planet that the thinks disrespects the culture of the Kree. The challenge for the Guardians isn’t just coming up with a plan to stop Ronan, it is to overcome their own selfishness, work together, and convince enough of their enemies that it serves their own interests to join the fight. Of course, this is a superhero movie, so they succeed, and their foes are vanquished for now. But it happens in ways that will surprise you.